/*******************************************************************************
 * Copyright (c) 2008 IBM Corporation and others. All rights reserved. This program and the
 * accompanying materials are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html Contributors: IBM Corporation - initial API and
 * implementation Jens Lukowski/Innoopract - initial renaming/restructuring
 *******************************************************************************/
package org.eclipse.wst.xml.ui.internal.preferences;

import org.eclipse.jface.preference.PreferencePage;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.ScrolledComposite;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Text;
import org.eclipse.ui.IWorkbench;
import org.eclipse.ui.IWorkbenchPreferencePage;
import org.eclipse.wst.xml.ui.internal.XMLUIMessages;

public class EmptyFilePreferencePage extends PreferencePage implements IWorkbenchPreferencePage {

  private Composite createComposite(Composite parent, int numColumns) {
    noDefaultAndApplyButton();

    Composite composite = new Composite(parent, SWT.NULL);

    // GridLayout
    GridLayout layout = new GridLayout();
    layout.numColumns = numColumns;
    composite.setLayout(layout);

    // GridData
    GridData data = new GridData(GridData.FILL);
    data.horizontalIndent = 0;
    data.verticalAlignment = GridData.FILL;
    data.horizontalAlignment = GridData.FILL;
    composite.setLayoutData(data);

    return composite;
  }

  protected Control createContents(Composite parent) {
    Composite composite = createScrolledComposite(parent);

    String description = XMLUIMessages.EmptyFilePreferencePage_0;
    Text text = new Text(composite, SWT.READ_ONLY);
    // some themes on GTK have different background colors for Text and Labels
    text.setBackground(composite.getBackground());
    text.setText(description);

    setSize(composite);
    return composite;
  }

  private Composite createScrolledComposite(Composite parent) {
    // create scrollbars for this parent when needed
    final ScrolledComposite sc1 = new ScrolledComposite(parent, SWT.H_SCROLL | SWT.V_SCROLL);
    sc1.setLayoutData(new GridData(GridData.FILL_BOTH));
    Composite composite = createComposite(sc1, 1);
    sc1.setContent(composite);

    // not calling setSize for composite will result in a blank composite,
    // so calling it here initially
    // setSize actually needs to be called after all controls are created,
    // so scrolledComposite
    // has correct minSize
    setSize(composite);
    return composite;
  }

  public void init(IWorkbench workbench) {
  }

  private void setSize(Composite composite) {
    if (composite != null) {
      // Note: The font is set here in anticipation that the class inheriting
      //       this base class may add widgets to the dialog.   setSize
      //       is assumed to be called just before we go live.
      applyDialogFont(composite);
      Point minSize = composite.computeSize(SWT.DEFAULT, SWT.DEFAULT);
      composite.setSize(minSize);
      // set scrollbar composite's min size so page is expandable but
      // has scrollbars when needed
      if (composite.getParent() instanceof ScrolledComposite) {
        ScrolledComposite sc1 = (ScrolledComposite) composite.getParent();
        sc1.setMinSize(minSize);
        sc1.setExpandHorizontal(true);
        sc1.setExpandVertical(true);
      }
    }
  }
}
